There's no reason to believe that the workers there aren't making $15 or $20/hr. Sure, they might be minimum wage, but there are fast food places by me advertising $25/hr for first shift workers and they can't find anyone. The stadiums in the nearest city are fully staffed, so it's unlikely they're getting minimum wage.

It's certainly likely, bordering on probable, that a lot of the people getting tips now that didn't get tips 4-5 years ago are making good money without tips and that's just extra.

For a specific example, I go to a local Subway every now and then, and they advertise hiring at $18/hr to start, more for part time, less desirable shifts, etc. Their POS lets you tip 18%, 20%, 25%, or "Skip" ($0) unless you do custom. I obviously don't know their revenue but they've been in business years while others in the same shopping center have come and gone, so they've got to be doing decent volume. There's no reason to think they're not getting several dollars and hour (e.g. several thousand dollars a year) in tips beyond their salary. It's not because they're underpaid, it's because people will tip if you make that the default.

Sorry, but you gotta tip in those scenarios. You have correctly identified the problem, and you know it isn't the workers' fault. Still, they aren't getting paid enough. It shouldn't be our job to spread money around evenly, but here we are. You can afford the game, you can afford the beer, you can afford to tip them.